tailieunhanh - Fundamentals of Corporate Finance Phần 6

Giả sử rằng bạn được cung cấp cơ hội để chơi trò chơi sau. Bạn bắt đầu bằng cách đầu tư $ 100. Sau đó, hai tiền xu lộn. Đối với mỗi đầu mà đi lên, bắt đầu từ sự cân bằng của bạn sẽ được tăng thêm 20%. | 320 section three figure Historical returns on major asset classes 1926-1998. Average return percent Standard deviation percent in ra ip o p 1 50 45 40 35 30 25 20 15 10 5 0 -10 10 in ra ip o p 1 -40 -30 -20 -10 10 Rate of return percent 9 8 Common stocks 7 6 - 5 4 3 2 1 0 in ra ip o p 1 50 I- 45 Inflation 40 35 30 25 20 15 10 5 0 -10 10 Rate of return percent Source Stocks Bonds Bills and Inflation 1999 Yearbook 1999 Ibbotson Associates Inc. Based on copyrighted works by Ibbotson and Sinquefield. All Rights Reserved. Used with permission. calculated. Suppose that you are offered the chance to play the following game. You start by investing 100. Then two coins are flipped. For each head that comes up your starting balance will be increased by 20 percent and for each tail that comes up your starting balance will be reduced by 10 percent. Clearly there are four equally likely outcomes Introduction to Risk Return and the Opportunity Cost of Capital 321 Head head You make 20 20 40 Head tail You make 20 - 10 10 Tail head You make -10 20 10 Tail tail You make -10 - 10 -20 There is a chance of 1 in 4 or .25 that you will make 40 percent a chance of 2 in 4 or .5 that you will make 10 percent and a chance of 1 in 4 or .25 that you will lose 20 percent. The game s expected return is therefore a weighted average of the possible outcomes Expected return probability-weighted average of possible outcomes .25 X 40 .5 X 10 .25 X -20 10 If you play the game a very large number of times your average return should be 10 percent. Table shows how to calculate the variance and standard deviation of the returns on your game. Column 1 shows the four equally likely outcomes. In column 2 we calculate the difference between each possible outcome and the expected outcome. You can see that at best the return could be 30 percent higher than expected at worst it could be 30 percent lower. These deviations in column 2 illustrate the spread of possible .